Tested on latest dev build. Using dolphin bar my controllers seem to connect fine. Launch dolphin, each controller vibrates. Only player 1 seems to be able to stay connected. Once I press a button on any other wiimote every light on the controller lights up steady and Dolphin say "Player X disconnected".

After attempting to relaunch Dolphin no wiimotes will connect with dolphin, even though they are connected appropriately through Dolphinbar (ie the light for P1, P2 corresponds to the controllers being synced). Under Dolphin Controller Configuration for wiimotes it says "A supported Bluetooth device could not be found, so you must connect Wii Remotes manually."

EDIT: So unplugging the Dolphin Bar, plugging back in and starting up Wii Sports Resort I was able to connect all 3 of my wiimotes. I then stopped that game and tried to load a different game (Price is Right), only player 1's controller held sync. The other two controllers said they were connected but the moment I pressed any button on either they disconnected and the light went from just whatever player they were to all 4 lights being lit up on the wiimote.

EDIT 2: I attempted to update DolphinBars firmware but it failed with the message "it's a different product, the firmware is not matched, cant update it!" According to amazon it turns out there are two separate versions of the DolphinBar, and I own the older one. So I tried the firmware update prior to the latest one from MayFlash's website. It says my firmware is up-to-date on my DolphinBar.